The present disclosure relates to switched mode power supplies, and, more particularly to inductor current sensing in a switched mode power supply. Switched mode power supplies are becoming increasingly common as power supplies for a great variety of applications. In switched mode power supplies an input voltage is modulated by a switch and the modulated waveform is passed through an inductor, rectified and filtered to provide an output of controlled value. In order to control the switching and therefore the output, it can be helpful to know current passing through the inductor.